True, but the difference is the way the downstreaming happens. Currently there is no bandwidth issues when millions of people all watch TV from a coax signal. in addition, there are tens of thousands of sources for those coax TV signals, as each cable company is just a simple re-broadcaster of someone else's content. In addition to the millions of people that receive their signals over the air.
Internet streaming is an entirely different beast. There are fewer sources...

If you had 50 million American households all watching Internet TV at the same time, multiply that by 300 million TVs all around the world, all watching TV on the Internet at the SAME TIME, the net would crash. This would happen every hour, of every day....... Like I said, the Internet is not react for this yet. Netflix alone is bringing Internet traffic to its knees.
We don't have the Internet infrastructure in place yet to make a world wide Internet TV a practical...

Netflix, is wreaking havoc on the entire Internet, and is forcing ISPs everywhere to re-think their download polices.
I'm sorry, but the net is just not ready for the type of traffic that a 100% let's-get-it-right-the-first-time service that Apple needs to deliver. Everything needs fiber optics first. Then DL limits will not be an issue. So, that leaves over the air. I really can't see how that's going to work. The cable and telcos will protect that turf until they die....

The number one thing that has to happen for ANY type of Internet based TV, is for all customers to be connected via fiber-optics. That is a minimum. And that is years and years away. That will cost billions for the infrastructure to be put into place.
Then I can see Apple making deals with cable companies, or even their own data center. When I downloaded Lion, it took one and a half hours! How long would it take before the content I wanted to watch was even ready for...

I agree completely. I don't want to waste my bandwidth watching TV shows. That's rediculous. I would top out my monthly limit in a few days. I find it difficult enough just watching streaming videos from YouTube.....
As its been said many times before, it's the content that's the thing. You can have the best interface in the world, but if you don't have content..... Jeez, here in Canada we can't even listen to Pandora, or even watch American commercials. How the hell...

Luckily, up here in the great white north, (Canada), my carrier (Fido) does not charge extra for tethering. When I bought my OG iPad back on day one from a US Apple store, I bought a wifi only version, with the express plan to be able to tether my iPhone with it some day. Luckily, when the personal hotspot feature in iOS became available, I was finally able to implement my plan.
It seems to me, as others have posted, with a pay-for tethering, you are being billed twice...